In the recovery of natural or manufactured resources from municipal or other waste, it has been found that many recovered materials have value in either their recovered form or in subsequently modified form. Glass is one such material which may be recovered and reused.
One simple method of recovering glass is to process the resultant product produced by incineration of municipal waste, or the product produced by incineration of previously segregated glass and metal items. The products of such incineration are usually charred masses or agglomerations of partly congealed unburned metal and glass wherein metal components of the mixture are often fused directly to the glass constituents.
Aluminum constitutes a relatively large part of such waste and may be removed by flattening and filtering, for example, so that substantially only glass or silica and magnetic materials remain, the slight amount of other nonmagnetic metals being negligible.
However, it has been found that subsequent processing of the glass and magnetic materials mixture is quite difficult and objectionable. For example, during incineration the magnetic materials often become fused to the glass particles. While much of the magnetic materials can be separated from the glass during subsequent milling or other process where the materials are reduced to small particle size, many times the small glass particles still have magnetic metal fused to them, and attempts to separate such particles results in the inclusion of some metal which renders the resultant product impure. Furthermore, such processing creates a considerable amount of harmful dust which is often ejected into the surrounding atmosphere.
Known prior art systems employ particle conveying systems which move the materials at relatively high velocity. Consequently, since the glass and metal particles are highly abrasive, wear upon the conveying systems is objectionably high.